cache_factory Class Reference

The cache factory class. More...

Inheritance diagram for cache_factory:

Public Member Functions
	create_cache (cache_definition $definition)
	Common public method to create a cache instance given a definition.
	create_cache_from_definition ($component, $area, array $identifiers=array(), $unused=null)
	Creates a cache object given the parameters for a definition.
	create_cache_from_params ($mode, $component, $area, array $identifiers=array(), array $options=array())
	Creates an ad-hoc cache from the given param.
	create_config_instance ($writer=false)
	Creates a cache config instance with the ability to write if required.
	create_definition ($component, $area, $unused=null)
	Creates a definition instance or returns the existing one if it has already been created.
	create_lock_instance (array $config)
	Returns a lock instance ready for use.
	create_store_from_config ($name, array $details, cache_definition $definition)
	Creates a store instance given its name and configuration.
	get_adhoc_caches_in_use ()
	Gets all adhoc caches that have been used within this request.
	get_caches_in_use ()
	Returns the cache instances that have been used within this request.
	get_state ()
	Returns the current state of the cache API.
	get_store_instances_in_use (cache_definition $definition)
	Returns an array of cache stores that have been initialised for use in definitions.
	is_disabled ()
	Returns true if the cache API has been disabled.
	is_initialising ()
	Returns true if the cache is currently initialising itself.
	is_updating ()
	Returns true if the cache is currently updating itself.
	reset_cache_instances ()
	Resets the stores, clearing the array of created stores.
	set_state ($state)
	Updates the state fo the cache API.
	stores_disabled ()
	Returns true if the cache stores have been disabled.
	updating_finished ()
	Informs the factory that the upgrading has finished.
	updating_started ()
	Informs the factory that the cache is currently updating itself.

Static Public Member Functions
static	disable_stores ()
	Disables cache stores.
static	get_administration_display_helper ()
	Returns an instance of the current display_helper.
static	get_disabled_writer ()
	Gets the cache_config_writer to use when caching is disabled.
static	instance ($forcereload=false)
	Returns an instance of the cache_factory class.
static	reset ()
	Resets the arrays containing instantiated caches, stores, and config instances.

Public Attributes
const	STATE_DISABLED = 10
	The cache has been disabled.
const	STATE_ERROR_INITIALISING = 9
	The cache encountered an error while initialising.
const	STATE_INITIALISING = 1
	The cache is in the process of initialising itself.
const	STATE_READY = 3
	The cache is ready to use.
const	STATE_SAVING = 2
	The cache is in the process of saving its configuration file.
const	STATE_STORES_DISABLED = 11
	The cache stores have been disabled.
const	STATE_UNINITIALISED = 0
	The cache has not been initialised yet.
const	STATE_UPDATING = 4
	The cache is currently updating itself.

Protected Member Functions
	__construct ()
	Protected constructor, please use the static instance method.
	create_dummy_store (cache_definition $definition)
	Creates a dummy store object for use when a loader has no potential stores to use.

Static Protected Member Functions
static	disable ()
	Disables as much of the cache API as possible.

Protected Attributes
array	$cachesfromdefinitions = array()
	An array containing caches created for definitions.
array	$cachesfromparams = array()
	Array of caches created by parameters, ad-hoc definitions will have been used.
array	$configs = array()
	An array of configuration instances.
array	$definitions = array()
	An array of initialised definitions.
array	$definitionstores = array()
	An array of stores organised by definitions.
array	$lockplugins = array()
	An array of lock plugins.
int	$state = 0
	The current state of the cache API.
array	$stores = array()
	An array of instantiated stores.

Static Protected Attributes
static core_cache local administration_display_helper	$displayhelper = null
	The current cache display helper.
static cache_factory	$instance
	An instance of the cache_factory class created upon the first request.

Detailed Description

The cache factory class.

This factory class is important because it stores instances of objects used by the cache API and returns them upon requests. This allows us to both reuse objects saving on overhead, and gives us an easy place to "reset" the cache API in situations that we need such as unit testing.

Copyright

2012 Sam Hemelryk

License

http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

Member Function Documentation

create_cache()

cache_factory::create_cache

(

cache_definition

$definition

)

Common public method to create a cache instance given a definition.

This is used by the static make methods.

Parameters

cache_definition

$definition

Return values

cache_application|cache_session|cache_store

Exceptions

coding_exception

Reimplemented in cache_factory_disabled.

create_cache_from_definition()

cache_factory::create_cache_from_definition	(		$component,
			$area,
		array	$identifiers = array(),
			$unused = null )

Creates a cache object given the parameters for a definition.

If a cache has already been created for the given definition then that cache instance will be returned.

Parameters

string	$component
string	$area
array	$identifiers
string	$unused	Used to be data source aggregate however that was removed and this is now unused.

Return values

cache_application|cache_session|cache_request

Reimplemented in cache_factory_disabled.

create_cache_from_params()

cache_factory::create_cache_from_params	(		$mode,
			$component,
			$area,
		array	$identifiers = array(),
		array	$options = array() )

Creates an ad-hoc cache from the given param.

If a cache has already been created using the same params then that cache instance will be returned.

Parameters

int	$mode
string	$component
string	$area
array	$identifiers
array	$options	An array of options, available options are: simplekeys : Set to true if the keys you will use are a-zA-Z0-9_ simpledata : Set to true if the type of the data you are going to store is scalar, or an array of scalar vars staticacceleration : If set to true the cache will hold onto data passing through it. staticaccelerationsize : The maximum number of items to hold onto for acceleration purposes.

Return values

cache_application|cache_session|cache_request

Reimplemented in cache_factory_disabled.

create_config_instance()

cache_factory::create_config_instance

(

$writer = false

)

Creates a cache config instance with the ability to write if required.

Parameters

bool

$writer

If set to true an instance that can update the configuration will be returned.

Return values

cache_config|cache_config_writer

Reimplemented in cache_factory_disabled.

create_definition()

cache_factory::create_definition	(		$component,
			$area,
			$unused = null )

Creates a definition instance or returns the existing one if it has already been created.

Parameters

string	$component
string	$area
string	$unused	This used to be data source aggregate - however that functionality has been removed and this argument is now unused.

Return values

cache_definition

Exceptions

coding_exception

If the definition cannot be found.

Reimplemented in cache_factory_disabled.

create_dummy_store()

cache_factory::create_dummy_store ( cache_definition $definition )

protected

Creates a dummy store object for use when a loader has no potential stores to use.

Parameters

cache_definition

$definition

Return values

cachestore_dummy

create_lock_instance()

cache_factory::create_lock_instance

(

array

$config

)

Returns a lock instance ready for use.

Parameters

array

$config

Return values

cache_lock_interface

create_store_from_config()

cache_factory::create_store_from_config	(		$name,
		array	$details,
		cache_definition	$definition )

Creates a store instance given its name and configuration.

If the store has already been instantiated then the original object will be returned. (reused)

Parameters

string	$name	The name of the store (must be unique remember)
array	$details
cache_definition	$definition	The definition to instantiate it for.

Return values

boolean|cache_store

Reimplemented in cache_factory_disabled.

disable()

static cache_factory::disable ( )

staticprotected

Disables as much of the cache API as possible.

All of the magic associated with the disabled cache is wrapped into this function. In switching out the factory for the disabled factory it gains full control over the initialisation of objects and can use all of the disabled alternatives. Simple!

This function has been marked as protected so that it cannot be abused through the public API presently. Perhaps in the future we will allow this, however as per the build up to the first release containing MUC it was decided that this was just to risky and abusable.

disable_stores()

static cache_factory::disable_stores ( )

static

Disables cache stores.

The cache API will continue to function however none of the actual stores will be used. Instead the dummy store will be provided for all cache requests. This is useful in situations where you cannot be sure any stores are working.

In order to re-enable the cache you must call the cache factories static reset method: // Disable the cache factory. cache_factory\disable_stores(); // Re-enable the cache factory by resetting it. cache_factory\reset();

get_adhoc_caches_in_use()

cache_factory::get_adhoc_caches_in_use

(

)

Gets all adhoc caches that have been used within this request.

Return values

cache_store[]

Caches currently in use

get_administration_display_helper()

static cache_factory::get_administration_display_helper ( )

static

Returns an instance of the current display_helper.

Return values

core_cache\administration_helper

get_caches_in_use()

cache_factory::get_caches_in_use

(

)

Returns the cache instances that have been used within this request.

Since

Moodle 2.6

Return values

array

get_disabled_writer()

static cache_factory::get_disabled_writer ( )

static

Gets the cache_config_writer to use when caching is disabled.

This should only be called from cache_factory_disabled.

Return values

cache_config_writer

get_state()

cache_factory::get_state

(

)

Returns the current state of the cache API.

Return values

int

get_store_instances_in_use()

cache_factory::get_store_instances_in_use

(

cache_definition

$definition

)

Returns an array of cache stores that have been initialised for use in definitions.

Parameters

cache_definition

$definition

Return values

array

instance()

static cache_factory::instance ( $forcereload = false )

static

Returns an instance of the cache_factory class.

Parameters

bool

$forcereload

If set to true a new cache_factory instance will be created and used.

Return values

cache_factory

Reimplemented in cache_factory_disabled.

is_disabled()

cache_factory::is_disabled

(

)

Returns true if the cache API has been disabled.

Return values

bool

Reimplemented in cache_factory_disabled.

is_initialising()

cache_factory::is_initialising

(

)

Returns true if the cache is currently initialising itself.

This includes both initialisation and saving the cache config file as part of that initialisation.

Return values

bool

is_updating()

cache_factory::is_updating

(

)

Returns true if the cache is currently updating itself.

Return values

bool

reset_cache_instances()

cache_factory::reset_cache_instances

(

)

Resets the stores, clearing the array of created stores.

Cache objects still held onto by the code that initialised them will remain as is however all future requests for a cache/store will lead to a new instance being re-initialised.

set_state()

cache_factory::set_state

(

$state

)

Updates the state fo the cache API.

Parameters

int

$state

Return values

bool

stores_disabled()

cache_factory::stores_disabled

(

)

Returns true if the cache stores have been disabled.

Return values

bool

updating_finished()

cache_factory::updating_finished

(

)

Informs the factory that the upgrading has finished.

This forces the state back to ready.

updating_started()

cache_factory::updating_started

(

)

Informs the factory that the cache is currently updating itself.

This forces the state to upgrading and can only be called once the cache is ready to use. Calling it ensure we don't try to reinstantite things when requesting cache definitions that don't exist yet.

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The documentation for this class was generated from the following file:

• cache/classes/factory.php